How PAGASA Wind Signals Work
A PAGASA tropical cyclone wind signal states two things at once: a wind speed range in kph, and a lead time, the number of hours before that wind speed is expected to prevail in a given area. On first issuance, Signal No. 1 gives 36 hours of lead time, while Signal No. 4 and No. 5 give 12 hours, since those are typically raised only once the wind field is already close.
Each signal also carries a separate damage estimate for three construction categories: low risk structures (engineered buildings), medium risk structures (standard residential construction), and high risk structures (light material and makeshift housing). The same wind speed range produces very different outcomes across those three categories, which is why the signal table below is broken out by structure type rather than a single damage description.
Quick Reference
Lead time and wind speed range for each signal, on first issuance.
| Signal | Lead Time | Wind Speed | High Risk Structures |
|---|---|---|---|
| No. 1 | 36 hrs | 30 to 60 kph | Light damage |
| No. 2 | 24 hrs | 61 to 120 kph | Heavy damage |
| No. 3 | 18 hrs | 121 to 170 kph | Heavy damage |
| No. 4 | 12 hrs | 171 to 220 kph | Very heavy damage |
| No. 5 | 12 hrs | More than 220 kph | Widespread damage |
Slight damage to houses of very light materials or makeshift structures in exposed communities. Some banana plants are tilted, a few downed, and leaves are generally damaged.
Light to moderate damage to exposed communities overall.
- Unshielded, old, dilapidated schoolhouses, makeshift shanties, and other light material structures are partially damaged or unroofed.
- A number of nipa and cogon houses may be partially or totally unroofed.
- Some old galvanized iron (G.I.) roofs may be peeled or blown off.
- Some old wooden electric posts are tilted or downed.
- Some damage to poorly constructed signs and billboards.
- Most banana plants, a few mango trees, ipil-ipil, and similar trees are downed or broken. Some coconut trees may be tilted, with a few broken.
- Rice and corn may be adversely affected. Considerable damage to shrubbery, with some heavy-foliaged trees blown down.
Moderate to heavy damage to exposed communities overall, a step up in severity from Signal No. 2 at the same structure types.
- Unshielded, old, dilapidated schoolhouses, makeshift shanties, and other light material structures are partially damaged or unroofed.
- A number of nipa and cogon houses may be partially or totally unroofed.
- Some old galvanized iron (G.I.) roofs may be peeled or blown off, and old wooden electric posts tilted or downed.
- Some damage to poorly constructed signs and billboards.
- Most banana plants, a few mango trees, ipil-ipil, and similar trees are downed or broken. Some coconut trees may be tilted, with a few broken.
- Rice and corn may be adversely affected. Considerable damage to shrubbery, with some heavy-foliaged trees blown down.
Considerable damage to light material structures, with up to 75 percent totally or partially destroyed and complete roof structure failures.
- Many medium-built houses are unroofed, some with collapsed walls, and extensive damage to doors and windows.
- A few houses of first-class materials are partially damaged.
- All signs and billboards are blown down. Near total damage to banana plantations.
- Most mango trees, ipil-ipil, and similar large trees are downed or broken.
- Coconut plantations may suffer extensive damage. Rice and corn plantations may suffer severe losses.
Almost total damage to light material structures, especially in highly exposed coastal areas. This is the highest level in PAGASA's Modified Tropical Cyclone Warning System.
- Complete roof failure on many residences and industrial buildings.
- Most residential and institutional buildings of mixed construction may be severely damaged.
- Electrical power and communication services severely disrupted.
- All signs and billboards are blown down. Total damage to banana plantations.
- Most tall trees are broken, uprooted, or defoliated. Coconut trees are stooped, broken, or uprooted. Few plants and trees survive.
Frequently Asked Questions
What does PAGASA Signal No. 1 mean?
Signal No. 1 is raised when winds of 30 to 60 kph are prevailing or expected within 36 hours. Impact is generally limited to very light damage, though banana plants and makeshift structures in exposed communities may already show some damage.
Why does the lead time get shorter as the signal number goes up?
Lead time reflects how soon the stated wind speed is expected to arrive, not the strength of the storm alone. Signal No. 1 carries a 36 hour lead time on first issuance, while Signal No. 4 and No. 5 carry 12 hours, since higher signals are typically raised once a stronger, faster-arriving wind field is already close.
What is the difference between low, medium, and high risk structures in PAGASA's system?
PAGASA rates expected wind damage separately for three construction categories. Low risk structures are engineered buildings built to withstand strong wind loads, medium risk structures are standard residential construction, and high risk structures are light material homes such as nipa, cogon, or makeshift housing, which sustain the most damage at every signal level.
Is PAGASA Signal No. 5 the same as a super typhoon?
They measure different things. Signal No. 5 is a wind signal tied to sustained winds above 220 kph in a specific area, while super typhoon is a storm category based on the cyclone's maximum sustained winds overall. A super typhoon usually triggers Signal No. 5 in the areas closest to its center, but the two labels are not interchangeable.
Does a higher wind signal number also mean higher storm surge risk?
Not directly. Wind signals are based on wind speed and lead time, while storm surge risk depends on coastal geography, storm track, and central pressure. A coastal area under a lower wind signal can still face significant storm surge if the storm track puts it in the surge-prone quadrant.
Last updated: September 15, 2026. Source: PAGASA Modified Tropical Cyclone Warning System, Tropical Cyclone Wind Signals reference. Back to Typhoon Wiki →